Problem: I have to receive and alter untagged (that kind of tags to make a PDF barrier free) PDFs generated with all kinds of applications (MS Word, Distiller, InDesign ...), which I have to extend with tags with the function "add tags automatically", but this function moves characters and deletes vector paths in graphics (vector paths not always, but too often). Seems like a very serious bug to me. I am working with Acrobat DC with a CC-Account, but these symptoms appear with Acrobat X too.

My question: Is this really a bug? Is there a workaround, which I don't know?

My request to Adobe: if this is a bug, repair it, immediately! Please! It must be a bug ... a function, which deletes or moves elements in an unpredictable way from content of a PDF?

Hi Martin, you are referring to the "Autotag Document" feature in the Acrobat Pro accessibility tools, correct? If you have access to the source documents (e.g. MS Word) I generally get better results if I remediate accessibility as much as practical in the source application before converting to PDF. When auto-tagging a PDF in Acrobat Pro, I have found results vary - though I have not experienced the issues you describe. Sometimes I have content "disappear" due to Z order, but not get deleted or move about - at least as far as I recall. In cases where auto-tagging works poorly, I bite the bullet and tag manually - easier than fixing the many problems that auto-tagging can sometimes introduce.